Idk Flashcards
Primary controls
Elevator, rudder, ailerons
Y primary controls
Change airflow/pressure distribution over airfoils
Ailerons
Roll, yoke -> moves right aileron ^ left down = Dec lift on right wing
Elevator
Pitch of lateral axis(front to back), tail end of the plane on the horizontal stabilizer, yoke back = elevator^ = downwards aerodynamic force bc tail goes down= pitch up
Stabilator
Horizontal stabilizer and elevator that pivots from a central hinge
canard
stabilator for front wings, elevator attatched to trialing edge of canard to control pitch
rudder
yaw (when deflected into airflow, horizontal force is placed in opp direction called yaw) on vertical axis, doesn’t turn plane in air
flight control effectiveness
inc w speed bc more airflow over surface=more control
secondary flight controls
flaps, leading edge devices, spoliers, trim systems
flaps
attatched to trailing edge of wing, used during approach/ landing to inc lift so u can land at steeper angle w out needing to inc ur speed
4 forces
lift upward acting force, drag rearward acting force, weight downward acting force, thrust (foreward-acting ward force)
forces r in equilibrium during
unaccelerated flight, can include middle of climb not beinning or end tho
bernoulli’s principle
high speed flow (internal pressure of a fluid) is associated with low pressure and inverse
bernoulli application
applies to curved/cambered airfoils/wings bc when air flows along upper wing surface it travels a gat distance in same time than lower wing surface airflow creating dec pressure and inc lift
Canard
Like horizontal stabilizer but on front wings
Angle of attack
Angle between chord line and relative wind direction
Chord line
Straight line from leading to trailing edge of airfoil
Relative wind direction
Wind relative to wing airfoil
Stalls when
Any airspeed/altitude when crit AOA exceeded
Stall speed
Airspeed correlates to air density so when stall u stall at same speed
Spin
Aggravated stall where on wing less stalled, descend in corkscrew path, have to be stalled first
TO DO
1.1,1.6
Turn
Uses horizontal component of lift by using all primary controls
Stable airplanes
Return to OG pos/alt after disturbance, requires less effort to control
slotted flap
most common flap, igh pressure air from lower camber (opp of bournolli) is ducted (goes through a gap and out the top side) delaying airflow seperation
delaying airflow seperation
dec drag, inc lift
spoiler
high drag devices, inc drag, dec lift
trim system
stop having to use constant control on flight controls, inc antiservo tabs, trim tabs, ground adjustable tabs (on the trailing edge of elevator), when set up it turns down so plane pitches up bc nose pitches up but tail pitches down
longditudinal stability
depends on CG (center of gravity) and CL/CP (center of lift/pressure), chaning CP of wing affectts its aerodynamic balance and control
advancing throttle
inc AOA and ground spped
if CG exceeds CG limit
plane cant recover from stall, is less stable at all aispeeds, inc prossibility of inadvertent overstress
power reduced
plane pitches down bc downwash on the elvators from propellor slipstream is reduced and elevator effectiveness is reduced (When the plane’s power goes down, the wind hitting the back tail gets weaker, so the tail can’t push up as hard, making the front of the plane tilt down.)
downwash
air deflected backwards not downwards off airfoil (like when plane hovers over water and theres water ripples this is the downwashed air)
Torque effect
Left leaning tendency, greatest at low speed/ high AOA/high power (takeoff) bc propellor spins one way so newton third law (action gets equal reaction) balances out the slight rotation
P factor
Asymmetric propeller loading causes leftwards yaw at high AOA bc right side of propellor has a higher AOA= more thrust on right side
Load factor
Additional (airplane weight + centrifugal force) carried by the wings, varies w speed and lift available, so low speed= less lift= less excess load
Load factor at higher speeds
The greater the loaf the more lift required so u can stall at higher airspeeds when load is increased, but u always stall same airspeed in the end
Bank angle
Angle a plane tilts sideways during a turn, measured in horizontal plane
Inc bank angle
Inc load factor, bc the plane has to carry the load factor (plane + CENTRIFUGAL FORCE) which is bank angles difference between effective lift and total lift
Bank angle chart
load factor=airplane weight * load factor w the bank angle u have
Load factor (G units)
Multiple of the regular weight/ multiple of the force of gravity I.e. steady flight has load factor at 1.0, 60 degree bank angle is 2.0 bc centrifugal force adds, stall at a higher speed s inc load factor bc more lift is required for more weight
Accelerated stall
When plans forced to stall at 2x normal stalling speed, load factor= 4G
How to accelerated stall
Stall while turning quickly yi add extra force on the wings
Velocity vs G-load’s graph
White lines (gusts of diff strengths against airspeed to show resultant load factor), A-J (stalling speed Vs), C-H (maneuvering speed Va), D-G (max structural cruising speed Vno), E-F (never exceed speed Vne), C-E (positive limit load factor), I-G-F (negative limit load factor), blue means stalling
Limit load factor
Ratio (max sustainable load imposed vs airplane’s weight)
Exceeding limit load factor/ Vne
Structural damage/failure
Exceeding limit load factor/ Vne
Structural damage/failure
Ground effect
Ground affecting airflow patterns affecting airplane
Restricted vertical component of airflow
Affects wing’s upwash, downwash, and wingtip vortices
Upwash
Air reflected off of wing ahead/up/forwards
Wingtip vortices
Swirling airpatterns (vortex) created from tipless wing’s, drag/AOA reduced w lack of wingtip vortices (adding wingtip) bc it alters span-wise lift distribution
Affect of Dec wingtip vortices
Dec drag, Dec AOA so in ground effect a higher AOA is needed for same lift coefficient, or in steady flight regular AOA=inc lift
When ground effect
Less than air span above the ground
Ground effect cause
In ground effect, there’s less drag, more lift causing floating on landings (longer landings), or it can become airborne without the airspeed to do so above ground effect (if using insufficient speeds when out of ground effect u will have more drag causing hazards/marginal initial performance loss/come back to the runway)
